Laparoscopic myomectomy: a current view.
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Since 1990 laparoscopic myomectomy (LM) has provided an alternative to laparotomy when intramural and subserous myomata are to be managed surgically. However, this technique is still the subject of debate. Based on their own experience together with data from the literature, the authors report on the situation today regarding the operative technique for LM and the risks and benefits of the technique as compared with myomectomy by laparotomy. The operative technique comprises four main phases: hysterotomy; enucleation; suture of the myomectomy site and extraction of the myoma. LM offers the possibility of a minimally invasive approach to treat medium-sized (<9 cm) subserous and intramural myomata by surgery when there are only two or three of them. When conducted by experienced surgeons, the risk of peri-operative complications is no higher using this technique. Use of the laparoscopic route could reduce the haemorrhagic risk associated with myomectomy. LM could reduce also the risk of post-operative adhesions as compared with laparotomy. Spontaneous uterine rupture seems to be rare after LM but further studies are needed before it can be said whether the strength of the hysterotomy scars after LM is equivalent to that obtained after laparotomy. The risk of recurrence seems to be higher after LM than after myomectomy performed by laparotomy. (+info)
Effect of pyloric drainage on the healing of esophagogastric anastomoses in rats.
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BACKGROUND AND OBJECTIVES: Esophagogastric anastomotic leaks complicate 5% to 20% of esophagectomies for esophageal cancer and are responsible for approximately one-third of perioperative deaths. Poor gastric emptying is a predisposing factor for anastomotic leakage. An animal experiment was used to test the hypothesis that a pyloric drainage procedure (pyloromyotomy) would have a positive effect on esophagogastric anastomotic healing. METHODS: In 40 rats single-layer esophagogastric anastomoses were constructed with interrupted 7-0 polypropylene sutures. A pyloromyotomy was done in the experimental group (20 rats) but not in the control group (20 rats). Rats were sacrificed on the 7th postoperative day and their anastomoses were excised, mounted in a tensiometer, and distracted at 10 mm/min to measure breaking strength. After that, the hydroxyproline concentration (an indicator of wound collagen) of the anastomotic tissue was measured. RESULTS: There were no anastomotic leaks. The mean (and standard deviation) breaking strength of the esophagogastric anastomosis was 3.96 (1.14) N in the pyloromyotomy rats and 4.11 (0.75) N in the control rats (p = 0.64). The mean (and SD) hydroxyproline concentration in esophagogastric anastomotic tissue was 368.6 (31.5) nmol/mg in the pyloromyotomy rats and 376.6 (31.3) nmol/mg in the control rats (p = 0.77). CONCLUSION: Pyloric drainage (pyloromyotomy) did not have any effect on esophagogastric anastomotic wound healing in this rat model. (+info)
The skeletal response to matt and polished cemented femoral stems.
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We studied the effect of the surface finish of the stem on the transfer of load in the proximal femur in a sheep model of cemented hip arthroplasty. Strain-gauge analysis and corresponding finite-element (FE) analysis were performed to assess the effect of friction and creep at the cement-stem interface. No difference was seen between the matt and polished stems. FE analysis showed that the effects of cement creep and friction at the stem-cement interface on femoral strain were small compared with the effect of inserting a cemented stem. (+info)
Use of fibrin sealant for prosthetic mesh fixation in laparoscopic extraperitoneal inguinal hernia repair.
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OBJECTIVE: To evaluate the efficacy of mesh fixation with fibrin sealant (FS) in laparoscopic preperitoneal inguinal hernia repair and to compare it with stapled fixation. SUMMARY BACKGROUND DATA: Laparoscopic hernia repair involves the fixation of the prosthetic mesh in the preperitoneal space with staples to avoid displacement leading to recurrence. The use of staples is associated with a small but significant number of complications, mainly nerve injury and hematomas. FS (Tisseel) is a biodegradable adhesive obtained by a combination of human-derived fibrinogen and thrombin, duplicating the last step of the coagulation cascade. It can be used as an alternative method of fixation. METHODS: A prosthetic mesh was placed laparoscopically into the preperitoneal space in both groins in 25 female pigs and fixed with either FS or staples or left without fixation. The method of fixation was chosen by randomization. The pigs were killed after 12 days to assess early graft incorporation. The following outcome measures were evaluated: macroscopic findings, including graft alignment and motion, tensile strength between the grafts and surrounding tissues, and histologic findings (fibrous reaction and inflammatory response). RESULTS: The procedures were completed laparoscopically in 49 sites. Eighteen grafts were fixed with FS and 16 with staples; 15 were not fixed. There was no significant difference in graft motion between the FS and stapled groups, but the nonfixed mesh had significantly more graft motion than in either of the fixed groups. There was no significant difference in median tensile strength between the FS and stapled groups. The tensile strength in the nonfixed group was significantly lower than the other two groups. FS triggered a significantly stronger fibrous reaction and inflammatory response than in the stapled and control groups. No infection related to method of fixation was observed in any group. CONCLUSION: An adequate mesh fixation in the extraperitoneal inguinal area can be accomplished using FS. This method is mechanically equivalent to the fixation achieved by staples and superior to nonfixed grafts. Biologic soft fixation with FS will prevent early graft migration and will avoid the complications associated with staple use. (+info)
A Conewise Linear Elasticity mixture model for the analysis of tension-compression nonlinearity in articular cartilage.
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A biphasic mixture model is developed that can account for the observed tension-compression nonlinearity of cartilage by employing the continuum-based Conewise Linear Elasticity (CLE) model of Curnier et al. (J. Elasticity, 37, 1-38, 1995) to describe the solid phase of the mixture. In this first investigation, the orthotropic octantwise linear elasticity model was reduced to the more specialized case of cubic symmetry, to reduce the number of elastic constants from twelve to four. Confined and unconfined compression stress-relaxation, and torsional shear testing were performed on each of nine bovine humeral head articular cartilage cylindrical plugs from 6 month old calves. Using the CLE model with cubic symmetry, the aggregate modulus in compression and axial permeability were obtained from confined compression (H-A = 0.64 +/- 0.22 MPa, k2 = 3.62 +/- 0.97 x 10(-16) m4/N.s, r2 = 0.95 +/- 0.03), the tensile modulus, compressive Poisson ratio, and radial permeability were obtained from unconfined compression (E+Y = 12.75 +/- 1.56 MPa, v- = 0.03 +/- 0.01, kr = 6.06 +/- 2.10 x 10(-16) m4/N.s, r2 = 0.99 +/- 0.00), and the shear modulus was obtained from torsional shear (mu = 0.17 +/- 0.06 MPa). The model was also employed to predict the interstitial fluid pressure successfully at the center of the cartilage plug in unconfined compression (r2 = 0.98 +/- 0.01). The results of this study demonstrate that the integration of the CLE model with the biphasic mixture theory can provide a model of cartilage that can successfully curve-fit three distinct testing configurations while producing material parameters consistent with previous reports in the literature. (+info)
Tensile bond strength of a light-cured glass ionomer cement when used for bracket bonding under different conditions: an in vitro study.
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The purpose of this study was to investigate the tensile bond strength of a new light-cured resin reinforced glass ionomer cement (Fuji Ortho LC), following the bonding of stainless steel brackets to 40 extracted human premolar teeth under four different enamel surface conditions: (1) non-etched, moistened with water; (2) etched, moistened with water; (3) etched, moistened with human saliva; and (4) etched, moistened with human plasma. The etched surface produced a higher bond strength than the non-etched surface when contaminated with distilled water. Contamination with human saliva resulted in a further increase in bond strength whilst plasma contamination produced an even higher strength. However, one-way analysis of variance showed no statistically significant difference between the various groups. After debonding, enamel and bracket base surfaces were examined for residual adhesive. The location of the adhesive also indicated improved bonding to etched enamel. This investigation shows that regardless of enamel surface pretreatment or environment, Fuji Ortho LC provides an adequate strength for bonding of orthodontic brackets. (+info)
Effect of binary and ternary filler mixtures on the mechanical properties of composite resins.
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The mechanical strength of experimental light cure composites containing binary filler mixtures with various combinations of irregular and spherical macrofillers in various mixes, and the microfilled ternary system fillers were measured. The compressive strength of the binary mixtures between different shaped fillers was not related to mixing ratios, although it significantly increased as the filler size decreased. The mixing ratio was immaterial within the irregular filler mixture. The compressive strength of the binary mixtures within the spherical fillers increased as the mixing ratio increased while the filler size was relatively large, then the mixing ratio became insignificant as the filler size decreased under 1.4 microns. The compressive strength of the microfilled ternary fillers increased with the decrease in the macrofiller size and with the increase in the mixing ratio. A large diametrical tensile strength was found in several microfilled ternary mixtures containing different shaped macrofillers. (+info)
Addition of antibacterial agents to MMA-TBB dentin bonding systems--influence on tensile bond strength and antibacterial effect.
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To produce a bonding system which has both high bond strength and antibacterial properties, an antibacterial agent (vancomycin: VCM or metronidazol: MN) was added to the PMMA powder of 4-META/MMA-TBB resin (CB). The influence of the addition of an antibacterial agent on tensile bond strength to dentin and the antibacterial effect were investigated in this study. Forty-seven freshly extracted bovine first or second incisors were used to measure the tensile bond strength to dentin. The bond strengths to bovine dentin were not significantly decreased by addition of VCM (1%, 2%, 5%), or MN (1%) to CB (p < 0.05). The antibacterial effect of CB containing antibacterial agent on six strains of bacteria was investigated by the agar plate diffusion method, analyzing the appearance of the inhibition zone around a resin disk following anaerobic culturing. The resin disks containing VCM showed antibacterial effects on all of the strains examined; the widths of the inhibition zones were 4-15 mm. The resin disks containing MN showed antibacterial effects on three strains; the widths of the inhibition zones were 0-4 mm. It was thus possible to produce a bonding system with both antibacterial effect and high tensile bond strength by addition of VCM to PMMA powder. (+info)